Houdini 20.0 Shelf tools

Render Region shelf tool

Focuses the renderer on an area of interest.

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It can be faster to render only a small section of an image when using a render delegate in the viewer, as the subimage will resolve much faster than the full frame. The Render Region can be used to select and adjust a rectangular region of the full image. You can also focus rendering on an area of the image by clicking on it, so pixels near the click resolve faster (note that this requires the render delegate to support the click-to-focus API).

This tool is specfic to the LOPs viewer. In objects, use the render region.

Using the Render Region


Select a region of the image to render.

LMB click

Focus the rendering effort on the area clicked.


Pan the render region to a different area of the image.

RMB or mouse_wheel

Increase or decrease the size of the render region.

MMB double click

Center the render region around the click.


Clear the render region and return to full image rendering.


Clear the render focus and render all pixels with equal priority.

Holding down ⇧ Shift will make pan and scale movements more precise.

Click “Clear Render Region” in the toolbar to remove the render region and return to full frame rendering. Click “Clear Render Focus” in the toolbar to remove the render priority on the last clicked location to more evenly resolve the image.

The viewer can also show the scene outside the render region, rendered with the realtime viewport renderer, in order to give some context around the region and aid in navigation. This can be disabled with the Show GL Outside Region toggle in the toolbar.

Shelf tools

Using the shelf

  • Customize the shelf

    How to change the look of the shelf, change and rearrange its contents, and create your own shelf tools.